Ore roasting and calcining furnace



(No Model.) 0. W. DAVIS 8v G. D. OOL'BY.

ORE ROASTING AND GALCINING FURNACE.

No. 247,542. Patented Sept. 27,1881;

UNrTED STATES PATENT OFFICE.

OWEN W. DAvIs, F BANGOR, AND GEORGE 1). OOLBY, OF KATAHDIN IRON WORKS, MAINE.

ORE RQASTlNG-AND CALCINING FURNACE- SPECIFIOATION forming part of Letters Patent No. 247,542, dated September 27, 1881.

Application filed August 10, 1880. (No model.)

Maine, have invented certainnew and useful Improvements in ()re Roasting or Oalcining Furnaces; and we do hereby declare that the following is a full, clear, and exact description IO of the invention, that will enable others skilled in the art to which it appertains to make and use the same,reference being had to the accompanyin g drawing, forming a part of this specification, in which the figure shows a vertical :5 section.

Our invention consists of an improved furnace for roasting ore, and is more especially designed for treating those ores of iron which contain large proportions of sulphur, although its usefulness is not limited to such.

With the ordinary furnace the fumes of the sulphur reaching the top of the chimney and coming in contact with the cold air are condensed and aconsiderable portion falls back 2 5 upon the ore, Without doubt owing to the fact that the ascending draftis stronger at the sides of the chimney, allowing the central part to be comparatively without draft to oppose the descent of the products of condensation. Our

0 object is the remedy of this defect, and will be understood by reference to the accompanying drawing.

Ashows an ordinary furnace, circularin form,

having the usual fuel-arches, b, ore-drawing openings 0, and feed-openings (1, above which latter extends the chimney 0. Within this furnace we construct a hollow pier, f, circular in cross-section like the furnace itself, built of fire-brick to a height of some fifteen feet, (more or less,) so that its top may be above the intense heat. This pieris pierced with openings 9 from the level of the fuel-arches upward.

Upon its top we'erect a chimney or funnel, h,

for which purpose wrought-iron is a good material, extending it to the top of the furnace A at or near its point ofjunction with its surmounting chimney e, at which place it is braced and held in position by appropriate device sufficiently to sustain any blow or shock from the descending ore as it is fed to the furnace.

This funnel, with its supporting-pier supplied with openings connecting with the roasting ore, carries off the sulphur, forming a central draft, which, in connection with the chimney e, effectually prevents any return of the coilcentrated fumes, and converting the ore-roasting spacei into an annular chamber, with a perfect draft to its summit. Atj is an opening for conveniently cleaning the pier and funnel.

This form of furnacemay also be used to advantage in calcining lime and for similar purposes where a central draftwill be an advantage.

If preferred, the fire-brick pier maybe extended to the top of the furnace, thus dispensing with the funnel h; but this would not in any manner affect the operation of our invention, being simply an equivalent for said funnel.

We do not claim the devices shown in the patents of J. Benton, February 28, 1854, No. 10,574, and T. J. Ohubb, November 19, 1872,

No. 133,202. Neither of these shows an annular ore-roasting chamber, by which device we avoid the central core of cold air and little draft common to ordinary furnaces; nor does the central pier or conductor in either case communicate with the chimney or stack of the furnace, and through it to the air, so as to increase the central ascending draft. In the Benton patent it simply serves as a conductor to carry the distilled gases to a reservoir, serving the same function as the worm of a still, while that shown in Ohubbs patent is simply to introduce hot air into his gas-chamber.

We do not claim a suspended flue, as shown in the patent of W. S. Sampson, dated April 7, 1874. Thisdoes not form an annular oreroasting space, which is an important feature of our invention; nor would such a device operate to take the products of combustion from that part of the ore-body subjected to intense heat, as the flue would burn off up to a point where the ore was comparatively cool, thus diminishing the amount of internal draft. The fire-brick pier supporting the funnel and perforated, as described, is an essential part of our invention, enabling the heated products to be taken from the hottest part of the roasting ore-body, and thereby adding to the efficiency I00 of the internal draft in removing the sulphur, &e. Nor do we claim a portable chimney for brick-kilns, as shown in Hamiltons Patent No. 101,124.

By the use of the term annuiar we do not intend to limit ourselves to the precise form of furnace used, as the desired result might be produced by other shapes, the interior pier and funnel approximating in form to the surrounding furnace and producing a variation in the form of the ore-roasting space without changing the principle of our invention.

What we claim as our invention is An improved ore roasting or calcining furnace embodying an ordinary furnace, A, a central fire-brick pielyf, with openings j therein for cleaning the same, and openings 9, communicating with the surrounding orespace 1",

audafu n n e17h,supportcdbysaidpierfixten'd- 

